.mengceng {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: #000000;
  opacity: 0.5;
  z-index: 998;
}
.erweima_div {
  display: none;
  width: 344px;
  height: 344px;
  position: fixed;
  z-index: 999;
  left: 50%;
  margin-left: -172px;
  top: 50%;
  margin-top: -172px;
}
.erweima_div img {
  float: left;
  width: 344px;
  height: 344px;
}
